Such a stern aggregate is known from the applicant's previous NO-PS No. 158 335, the object of which was to reduce dimensions, especially the transversal dimension, of the lower portion of the housing surrounding the propel shaft and screw shaft with bearings by using universal Joints between the propel shaft and the screw shaft.
In such a stern aggregate reversal of the direction of screw rotation may either be achieved by the aid of a gearbox in said inboard engine or, if desired, in the transmission from the latter to the stern aggregate.
The last mentioned concept will require space between the engine and the stern of the craft and it will also form an independent unit which has to be mounted, i.e. inserted between the stern aggregate and the engine.